Buttonhole-cutter safety device for automatic buttonhole sewing machines



E. P. SPAINE Sept. 26, 1.939. BUTTONHOLE-CUTTER SAFETY DEVICE FORAUTOMATIC BUTTONHOLE SEWING MACHINES Filed July 16, 1938 e Sheets- Sheet1 amina E. P. SPAINE Sept. 26, 1939,

BUTTONHOLE-CUTTER SAFETY DEVICE FOR AUTOMATIC BUTTONHOLE SEW INGMACHINES Filed July 16, 1938 6 Sheets-Sheet 2 mime/1;

. mm k Q RN n m w E. P. SPAINE' Sepfia 26, 1939'.

BUTTONHOLE-CUT'I'ER SAFETY DEVICE FOR AUTOMATIC BUTTONHOLE SEWINGMACHINES Filed July 16, 1938 6 Sheets-Sheet 3 Hi In: A

a NW 9 m m 6 E. P. SPAINE 2,174,294 CUTTER SAFETY DEVICE FOR AUTOMATICBUTTONHOLE SEWING MACHINE:

Sept. 26, 1939'.

BUTTONHOLE- 6 Sheets-Sheet 4 Filed July 16, 1938 FIvLiI IIiII vl Sept.26, 1939. E, R mm; 2,174,294

BUTTONHOLE CUTTER SAFETY DEVICE FOR AUTOMATIC BUTT ONHOLE SEWINGMACHINES Filed July 16, 1938 s Sheets-Sheet 5 a Sheets-Sheet 6 E. PSPAINE iled July. 16, 1938 Sept. 26, 1939.

BUTTONI-IOLE-CUTTER SAFETY DEVICE FOR AUTOMATIC BUTTONHOLE sEwINGMACHINES Patented Sept. 26, 1939 UNITED STATES PATENT OFFICEBUTTONHOLE-CUTTER SAFETY DEVICE FOR AUTOMATIC BUTTONHOLE SEWING MA-CHINES Application July 16, 1938, Serial No. 219,489

7 Claims.

This invention relates to sewing machines of the automatic eyelet-endtype having buttonholecutting mechanism and buttonhole-working mechanismwhich are separately power driven and whose sequence of operations iscontrolled automatically. These machines are of two distinct types knownas cut-first machines and cut-after machines. In a cut-first machine thebuttonhole-cutting mechanism operates prior to the operation of thebuttonhole-working mechanism whereas, in a cut-after machine thebuttonhole-working mechanism operates prior to the operation of thebuttonhole-cutting mechanism. To prevent clashing of parts it is impor-16 tant that safety means be provided to prevent the possible operationof the buttonhole-cutting mechanism at times during abuttonhole-producing cycle other than the time when it should properlyoperate.

An object of the present invention is to provide a safety device of thecharacter described which will positively guard against the operation ofthe buttonhole-cutting mechanism over substantially the entire period ofoperation of the other mech- 5 anisms of the machine, so that thebuttonholecutting mechanism cannot possibly operate or be operated whileany working part of the machine is in a position to clash therewith orbe damaged thereby.

With the above and other objects in View, as will hereinafter appear,the invention comprises the devices, combinations and arrangements ofparts hereinafter set forth and illustrated in the accompanying drawingsof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

In the accompanying drawings, Fig. 1 is a right side elevation of abuttonhole sewing machine embodying the invention. Fig. 2 is a left sideelevation of the machine. Fig. 3 is a rear end elevation of the machine.Fig. 4 is a bottom plan view of the machine. Fig. 5 is a verticalsectional 4:! View taken transversely of the buttonhole-cutter shaft.Fig. 6 is a horizontal sectional view through the bracket-arm standardof the machine showing, in plan, the parts of the present safetymechanism associated with the buttonhole-cutter shaft. Fig. 7 is a viewsimilar to Fig. 5 with the parts drawn to a larger scale and showing theclamp-closing lever at the two extremes of its motion. Fig. 8 is a viewsimilar to Fig. 6 with the cutter-starter or so -called gate shown, infull lines, in running position and, in

dotted lines, in stopping position. Fig. 9 is a fragmentary view similarto Fig. 7 but showing the cutter-starter shifter lifted to itsineffective position. Fig. 10 is a view showing the lifter for thecutter-starter shifter latched in ineffective position. Fig. 11 is asimilar view showing the slight drop of the lifter lever for thecutter-starter shifter when the latch is unlatched by the operation ofthe stop-motion lever in starting the stitch-forming mechanism; thisslight drop preventing re-engagement of the latch when the stopmotionlever moves to stopping positon, Fig. 5. Fig. 12 is a view, similar toFigs. 7 and 10, showing recovery of the cutter-shifter blocking latchwhich is carried by the lever which lifts the cutter-starter shifted toineffective position; the recovery occurring when the cutter-starterreturns from full line (running) position, Fig. 9, to the dotted line(stopping) position, same figure. plate mounted on the cutter-startershifter.

In the preferred embodiment of the invention illustrated, the machineframe comprises a hollow box-like bed I from one end of which rises thestandard 2 of the overhanging bracket-arm 3 terminating in the head 4.

The stitch-forming mechanism is of the well known type embodying anupper endwise reciprocatory and laterally vibratory needle 5 andunderthread mechanism constructed substantially in accordance with thedisclosure of United States Patent No. 1,372,473, dated March 22, 1921,and comprising a turret 6, Fig. 1, which is turnable about a verticalaxis and carries threaded and.

non-threaded loopers, the former of which is shown at 1, and a pair ofloop-detainers one of which is shown at 8. The needle-actuatingmechanism is also mounted to turn about a vertical axis coincident withthe axis of the turret and the usual turning movements are imparted tothe upper needle and under looper mechanisms by the connected upper andlower sector gears 9 and I0, respectively, which are actuated in unisonby the usual connections with the cam-groove I I, Fig. 4, in thefeed-wheel I2. mechanism is more completely shown, for example, inUnited States Patent No. 1,162,207, November 30, 1915; Reissue PatentNo. 15,324, April 4, 1922; and Patent No. 1,534,017, April 21, 1925. Themechanism operates to rotate the stitchforming devices in one directionabout a vertical axis during the sewing around the eyelet-end of abuttonhole and to reversely rotate the stitchforming devices betweensewing periods to restore them to initial position. The stitch-formingde- Fig. 13 is a perspective view of the tooth- This well known vicesreceive their stitch-forming movements from the main sewing shaft l3which also drives the feed-cam l2 in step-by-step fashion, during thesewing, through the well known pin-and-starwheel drive M, Fig. 4, andthe usual train of gears l5, such as more completely shown in saidUnited States Reissue Patent No. 15,324.

The work-clamp is of the travelling type. It is first rapidly moved overthe bed to carry the work forwardly from initial or buttonhole-cuttingposition to sewing position then more slowly moved in step-by-stepfashion to place the stitches about the buttonhole, and then rapidlyreturned to initial position. It is constructed substantially inaccordance with said United States Reissue Patent No. 15,324, andcomprises the lower clamp-plates I6 and upper clamping feet I! which aredepressed into clamping engagement with the work by a rocking movementof two connected coaxial rock-shaft sections l8, |8 to the former ofwhich is connected an arm l9, Fig. 1, adapted to be depressed by theusual clamp-closing lever 20 actuated at the beginning of abuttonhole-making cycle by a camgroove 2|, Fig, 3, in a continuouslyrunning pulley 22 loose on the buttonhole-cutter shaft 23. A slide-pin24, carried by the rearwardly extending arm of the clamp-closing lever,is permitted to enter the cam-groove 2| for one revolution of the pulley22, whereupon it is ejected and latched in ejected position, asexplained in United States Patent No. 1,832,665, November 1'7, 1931; thepresent clamp-closing mechanism being constructed substantially inaccordance with the disclosure in said United States Patent No.1,832,665.

The clamp-plates l6 are carried by the crossslide plate 25, Fig. 4,which, in turn, is carried by the longitudinal slide-frame 26 to whichtravelling movements are imparted by the link-connection 21, Fig. 4,with the longitudinal feedlever 28 having a follower 29 working in thelongitudinal feed cam-groove 30 in the feed-wheel l2. The cross-slideplate 25 is shifted by the lever 3|, Fig. 4, which has the usualconnections with the feed-wheel l2 and removable patterncam 32 on thecross-shaft 33 which is geared at 34, Fig. 1, to the feed-cam |2, so asto run with the latter. The present feed mechanism is constructedsubstantially in accordance with the disclosure of said United StatesReissue Patent No. 15,324.

The rapid feed of the work-clamp from buttonhole-cutting position tosewing position and return is effected by the usual. constantly runningrapid feed drive-shaft 35, which through a worm-and-gear reduction 36,Fig. 4, drives the live element 31 of a clutch, the driven element 38 ofwhich is fast on the cross-shaft 33. It will be understood by referringto said United States Reissue Patent No. 15,324, that the withdrawal ofthe cone 39 from the driven clutch-element 38 cifects engagement of thedriving and driven clutch-elements 31, 38, while projection of the cone39 toward the driven clutch-element 38 effects the de-clutching of theparts 31, 38. The cone 39 is actuated by the usual arm 40 rigidlymounted on the endwise slidable rod 4| which is operated and controlledby the usual mechanism described in the Allen et al. United StatesPatent No. 1,711,483, of May 7, 1929.

The pattern-wheel 32, Fig. 2, which is removably carried by thecross-shaft 33, operates the usual tilting stop-motion lever 3 throughthe lever 42 and link 43 to control the period of action of thestitch-forming mechanism.

The buttonhole-cutting mechanism is constructed substantially inaccordance with the disclosure of said United States Patent No. 1,548,-815, and embodies the travelling buttonhole-cutter levers 44, 45, Fig.2, which are given their customary travelling and closing-and-openingmovements by suitable cams on the cutter-shaft 23 to which a singlerotation is imparted prior to sewing by the continuously rotating pulley22 acting through the usual one-revolution clutch. This well knownclutch comprises a springpressed clutch-tooth 46 which is carried by aslide-block 41 sliding radially of the disk 48 fast on the cutter-shaft23. This slide-block 41 is held in retracted position, Figs. 1 and 6, bythe head 49 of a cutter-clutch control or cutterstarter lever 50 havingan angular extension 5| at its rear end which is fulcrumed on thevertical M stud-pin 52. When the cutter-starter lever 50, 5| is shiftedfrom dotted line to full line position, Fig. 8, the head 49 thereofreleases the clutch-tooth slide 41 which is projected radially of thedisk 48 by the spring 46, Fig, 1 to carry the clutch-tooth 45 into thepath of movement of the internal teeth 53 on the pulley 22. Theconstruction and mode of operation of the cutter-starter 58, 5| andcutter-clutch 46, 41, 53 are more fully disclosed in said United StatesPatent No. 1,548,815. It will be understood that when the cutter-starteris shifted to running position, full lines in Fig. 8, the cutter-shaft23 is coupled to the power pulley 22 for one revolution only and isthereupon disconnected from the pulley 22 and brought to rest by theautomatic return of the cutter-starter 5!], 5| to stopping position(dotted lines, Fig. 8); this return being effected by the cam-groove 54in the hub of the disk .8 on the cutter-shaft acting upon thefollower-pin 55 which is carried by the lever 50 and enters thecam-groove 54.

The machine in which the invention is presently embodied is a cut-firstmachine, that is, the buttonhole-cutting mechanism is operated beforethe buttonhole-working mechanism is started. When the operator pressesdown upon the starting lever 56, Fig. 2, the starting rod 51, Fig. 1,is, through suitable connections, pulled downwardly to initiate theaction of the clampclosing mechanism. The down-pull on the starting rod51 effects the release of the slide-pin 24 which enters theclamp-closing cam-groove 2| in the pulley 22 and causes theclamp-closing lever 20 to be given clamp-closing and return impulses. Inthe clamp-closing impulse the lever 20 is moved from full line position,Fig. '7, to dotted line position and effects the closure of thework-clamp by striking and depressing the lever !9, Fig. 1, on thework-clamp. During the return impulse of the clamp-closing lever 20, thecutter-starter 5|), 5| is shifted to running position, shown in fulllines in Figs. '7 and 8. This is accomplished by the cutter-startershifter 58 which is in the form of a push-rod pivoted at 59 on theclamp-closing lever 20 and, at its other end, projecting through arectangular opening 60, Figs. 10 and 11, in the cutter-starter lever-arm5|. The portion of the push-rod 58 which projects through the opening 60in the lever-arm 5| has longitudinally adjustably mounted upon it aslideplate 6| formed with a depending tooth 62 which, When the push-rod58 rides upon the lower edge of the opening 60 in the cutter-starterlever-arm 5| under the influence of the spring 63, engages the 1ever-armand shifts the latter to full line or running position, Fig. 7, in thereturn impulse of the clamp-closing lever 28. This starts thecutter-shaft 23.

Means are provided to lift the push-rod or cutter-starter shifter 58 toan ineffective position Where it does not ride upon the lower edge ofthe opening 88 in the cutter-starter lever-arm 5|, and may reciprocateidly, if inadvertently operated, without tripping the buttonhole-cuttingmechanism into operation. To this end there is fulcrumed on thestud-screw 54 a safety-lever 65 which extends rearwardly over thecutter-shaft 23, Fig. '7, thence laterally at 66 under the cutterstartershifter 53, and thence rearwardly alongside the rearward end of thecutter-starter shifter 58. This safety lever 65 carries a follower roll61 in position to be engaged and lifted by a cam 68 on the cutter-shaft23. During the single rotation of the cutter-shaft 23, the cam 68 liftsthe safety-lever 65 to the position shown in Figs. 9 and where it isretained by engagement thereunder of the shoulder 69 of the springbiasedlatch-lever l8. In this elevated position of the safety-lever 65, thetransversely extending portion 58 thereof, Fig. 12, holds thecutterstarter shifter 58 in a safely elevated position with the tooth 62well above the bottom edge of the opening 60, where the bar 58 mayreciprocate idly, should the clamp-closing lever be inadvertentlyoperated.

Pivoted at H on the rear end of the safetylever 65 is a cutter-starterblocking latch 12 the tail of which is connected. to one end of thebiasing spring '83 for the latch l8. When the cutterstarter 58 isshifted to running or full-line position, Fig. '7, the shoulder 75thereon moves to a position over the nose M of the latch l2, so thatwhen the safety-lever 85 is lifted to the position shown in Fig. 9, thenose M is depressed by the shoulder l5. At the close of the singlerevolution of the cutter-shaft 23, the cutter-starter 5| is returned toits initial or stopping position, Fig. 12, and releases the nose M ofthe latch-lever 12 which springs upwardly behind the cutter-starter 5|and blocks the latter against rearward movement. This cutter-starterblocking latch-nose l4 locks the cutter-starter against accidental orinadvertent hand-initiated repeat operations at abnormal times during abuttonhole-producing cycle.

As the button hole cutter-shaft 23 nears the completion of its singlerotation, Fig. l, and with the parts of the safety mechanism heldelevated by the latch l8, Figs. 10 and 12, in safety position, thecam-nose it on the disk 83 depresses the arm 'i'i fast to the rock-shaftit the operation of which initiates the throwing in of the rapid-feedclutch M, 38 to start the rapid feed of the work-clamp frombuttonhole-cutting to buttonhole-sewing position, as disclosed in saidUnited States Patent No. 1,711,483.

The cross-shaft 33 which drives the feed-wheel i2 during this rapid-feedof the work-clamp, has mounted thereon, in the present instance, asafety cam-cylinder '59, Fig. 5, having a notch 8t therein affording atone side of the notch an angular drop-off shoulder 8!. When the machineis at rest, the cam i9 is in position for the notch 88 to receive theterminal extension 82 of an arm 83 fixed to the safety-lever 65. Whenthe buttonhole cutter-shaft is operated to cut the buttonhole, thesafety-lever 65 is lifted by the cam 68 to safety position and latchedthere by the latch 10. In this position of the safety-lever 55, the

extension 82 thereof is withdrawn from the notch 88 and is clear of thecam-cylinder 19 as the latter turns during the rapid-feed of theworkclamp from buttonhole-cutting to buttonholesewing position.

When the work-clamp arrives in buttonholesewing position, the rapid-feedis thrown out and the cam 84 on the pattern-wheel 32 acts upon the lever42 and link 43 to tilt the stop-motion lever s to its dotted lineposition to start the stitchforming mechanism.

The stop-motion lever s has fixed to its upper end a forwardly extendinghorizontal arm 85, which, in the tilting motion of the lever s to dottedline position, Fig. 2, strikes the tail B6 of the latch 10 and.disengages the shoulder 69 from the safety-lever 65 which dropssufficiently, Fig. 11, to prevent re-engagement of the shoulder 69thereunder when the stop-motion lever returns to its upright orfull-line position, Fig. 2, to stop the sewing operation. The amount ofdrop of the safety-lever 65 at this time is determined by the engagementof the safety-lever extension 82 with the cylindrical surface of thesafety-cam 19 on the cross-shaft 33 which at the beginning of therapid-feed movement of the shaft 33 is in position to take over from thelatch 10 the duty of holding the cutter-starter shifter 58 elevated inineffective position.

When the stop-motion lever s returns to its vertical (full line)position, Fig. 2, to stop the stitch-forming mechanism at the completionof the sewing of the buttonhole, the latch Ill is released and its nose10, Fig. 11, engages the side of the safety-lever 65 which is free todrop when released by the cylinder-cam 19.

At the completion of the sewing operation, the rapid-feed is againthrown in to drive the shaft 33 and feed-wheel to carry the work-clamprapidly back to its initial or starting position wherein the buttonholewas cut. During the return rapid-feed of the work-clamp thestitchforming mechanism is reversely rotated to restore the needle andturret to their starting positions. In some machines which are providedwith threadand cord-trimming mechanism such as disclosed in U. S. PatentNo. 1,711,483, of May '7, 1929; the actuation of the thread-cutter B1 isdependent upon the actuation of the lever 88, by the cam 89 in the gear34 on the cross-shaft 33. It is desirable that the safety-lever be heldin safety-position by the barrel-cam 19 until the work-clamp has beenreturned to initial position, the stitch-forming mechanism reverselyrotated to initial position, and until the thread-cutter scissors 81have been advanced to cut the thread and retracted, so that thebuttonhole-cutting mechanism cannot possibly be operated while any partof the machine is in position to clash therewith. To this end, thefollower-extension 82 of the safety-lever arm 83 is formed at itstrailing end-portion with an angular shoulder 82', Fig. '5, which, whenreleased by the drop-oif shoulder SI of the cam 19, allows thesafety-arm 85 to suddenly drop to the position shown in Fig. 7, ready tobegin another cycle of operations. The shoulder 8! is timed to pass theshoulder 82' after the cross-shaft 33 and all parts actuated therebyhave been restored substantially to starting position, clear of thefield of action of the buttonholecutter levers 44, 45.

Having thus set forth the nature of the invention, what I claim hereinis:

1. In a buttonhole sewing machine, buttonholecutting mechanism includinga cutter-shaft, buttonhole-working mechanism, power means to drive saidmechanisms, said buttonhole-working mechanism including stitch-formingmechanism, a work-clamp, a feed-wheel making one complete rotation perbuttonhole-producing cycle of the machine, said feed-wheel beingconnected to relatively move the stitch-forming mechanism and work-clampto sew about a buttonhole and to relatively shift the stitch-formingmechanism and work-clamp into and out of sewing relation prior andsubsequent to the sewing period, a clutch device including acutter-starter movable to a running position to start the operation ofthe buttonhole-cutting mechanism, spring-biased cutter-starter blockingmeans, a cam connected with the feed-wheel and having a long circularportion with connections to hold said blockln means in cutter-starterblocking position, said cam having an abrupt drop-oil shoulder torelease said blocking means instantly and permit the lat ter to moveunder the influence of its spring out of the path of said cutter-starterat the end of a buttonhole-producing cycle of operations or" themachine.

2. In a buttonhole sewing machine, buttonhole-cutting mechanismincluding a cutter-shaft, buttonhole-working mechanism, power means todrive said mechanisms, said buttonhole-working mechanism includingstitch-forming mechanism, a work-clamp, a feed-wheel making one completerotation per buttonhole-producing cycle of the machine, said feed-wheelbeing connected to relatively move the stitch-forming mechanism andwork-clamp to sew about a buttonhole and to relatively shift thestitch-forming mechanism and work-clamp into and out of sewing relationprior and subsequent to the sewing period, a clutch device including acutter-starter movable to a running position to start the operation ofthe buttonhole-cutting mechanism, spring-biased cutter-starter blockingmeans, a cam connected with the feed-wheel and having a long circularportion with connections to hold said blocking means in cutter-starterblocking position, said cam having a sudden drop-off to release saidblocking means and permit the latter to move out of the path of saidcutter-starter at the end of a buttonhole-producing cycle of operationsof the machine, means actuated by the button-hole cutter shaft toinitially move said cutter-starter blocking means to blocking position,and means actuated by the buttonhole-cutter shaft to start thebuttonhole working mechanism.

3. A buttonhole sewing machine having, in combination,buttonho1e-cutting mechanism including a cutter-shaft,buttonhole-working mechanism, the latter mechanism includingstitchforming mechanism, a work-clamp and a feedwheel with connectionsfor relatively moving the stitch-forming mechanism and Work-camp intoand out of sewing relation and to sew about a buttonhole, power means todrive the buttonholecutting and buttonhole-working mechanisms,clamp-closing mechanism, clutch means including a cutter-starter movableto a running position to connect the buttonhole-cutter shaft to itspower means, a cutter-starter shifter actuated by the clamp-closingmechanism, a cam on the buttonhole-cutter shaft and connections to movethe cutter-starter shifter to an ineffective position, a latch totemporarily hold said shifter in said ineffective position, meansactuated by the buttonhole working mechanism to trip said latch, a camconnected with the feed-wheel and having a circular portion, a followerarranged to bear upon said circular portion and take over the duty ofholding said cutter-starter shifter in ineffective position whenreleased by said latch, said cam having a sudden drop-off to permit saidcutter-starter shifter to move to effective position at the end of abuttonhole producing cycle of operations of the machine.

4. A buttonhole sewing machine having, in combination,buttonhole-cutting mechanism including a cutter-shaft,buttonhole-working mech anism, the latter mechanism includingstitchforming mechanism, a work-clamp, a feed-wheel with connections forrelatively moving the stitchforming mechanism and work-clamp into andout of sewing relation and to sew about a buttonhole, and a cross-shaftparallel to said cuttershaft and geared one-to-one to said feed-wheel,clutch means including a cutter-starter movable to a running position toconnect the cutter-shaft to its source of power, clamp-closingmechanism, a cutter-starter shifter actuated by the clamp-closingmechanism, a safety-lever arranged to move the cutter-starter shifter toan ineffective position, a cam on the cutter-shaft to so move saidlever, said lever having an extension reaching to said cross-shaft, anda cam on said cross-shaft operatively related to said leverextension andhaving a drop-off arranged to release said lever-extension at the closeof a buttonhole producing cycle.

5. A buttonhole sewing machine having, in combination,buttonhole-cutting mechanism, including a cutter-shaft,buttonhole-working mechanism, the latter including stitch-formingmechanism, a stop-motion device therefor including a tilting stop-motionlever, a work-clamp, a feedwheel with connections for relatively movingthe stitch-forming mechanism and work-clamp into and out of sewingrelation and to sew about a buttonhole, power means to drive thebuttonholecutting and buttonhole-working mechanisms, clamp-closingmechanism, clutch means including a cutter-starter movable to a runningposition to connect the cutter-shaft to its power means, acutter-starter shifter actuated by the clamp-closing mechanism, a cam onthe cuttershaft and connections to move the cutter-starter shifter to anineffective position, a latch to temporarily detain said shifter in saidineffective position, latch-tripping means actuated by the tiltingmotion of the stop-motion lever to stitchforming mechanism startingposition, a cam connected with the feed-wheel and having a circularportion, a follower arranged to bear upon said circular portion and takeover the duty of holding said cutter-starter shifter in ineffectiveposition when released by said latch, said cam having a sudden drop-offto permit said cutterstarter shifter to move to effective position atthe end of a buttonhole producing cycle of operations of the machine.

6. A buttonhole sewing machine having, in combination,buttonhole-cutting mechanism including a cutter-shaft,buttonhole-working mechanism, the latter mechanism includingstitchforming mechanism, a work-clamp and a feedwheel with connectionsfor relatively moving the stitch-forming mechanism and workclamp intoand out of sewing relation and to sew about a buttonhole, power means todrive the buttonhole-cutting and buttonhole-working mechanisms,clamp-closing mechanism, clutch-means including a cutter-starter movableto a running position to connect the cutter-shaft to its power means, acutter-starter shifter actuated by the clamp-closing mechanism, asafety-lever fulcrumed on an axis parallel to said cutter-shaft andarranged to move said cutter-starter shifter to an ineffective positionwhere it may idly perform the motion imparted to it by an untimelyoperation of the clamp-closing mechanism, a cam on the cutter-shaftarranged to move said safetylever to safety position, means to detainsaid safety-lever in safety position after said cuttershaft hasoperated, means on said safety-lever to block movement of saidcutter-starter to cutter-starting position when said safety-lever is insafety position, and means to release said safetylever at the close of abuttonhole-producing cycle of operations of the machine.

7. A buttonhole sewing machine having, in combination,buttonhole-cutting mechanism including a cutter-shaft,buttonhole-working mechanism, the latter mechanism includingstitchforming mechanism, a work-clamp and a feedwheel with connectionsfor relatively moving the stitch-forming mechanism and work-clamp intoand out of sewing relation and to sew about a buttonhole, power means todrive the buttonholecutting and buttonhole-working mechanisms,clamp-closing mechanism, clutch-means including a cutter-starter movableto a running position to connect the cutter-shaft to its power means, acutter-starter shifter actuated by the clamp-closing mechanism, safetymeans to hold said cutter-starter shifter in an ineffective positionwhere it may idly perform the motion imparted to it by an untimelyoperation of the clamp-closing lever, said safety means including apivoted element which, in safety position, blocks movement of saidcutter-starter to running position, the pivotal axis of said elementbeing transverse to the direction of the thrust imparted to said elementwhen blocking movement of the cutter-starter.

EDWARD P. SPAINE

